This massive circular pit is actually a technologically advanced simulator, designed to allow Space Marines to go up against virtual enemies, either alone or as a team. The whole of the pit is an empty circle with a 200m diameter. The roof is sealed over with adamantium meshing, 20m off the plasteel floor.

"Apex 472 is an uninhabited planet within the Expanse that provides a unique opportunity in exploration and exploitation. It is within the best interest of the Mechanicus that such a planet is surveyed for further use. Your pay will be …

Admiral Nathaniel Horne calls to all able bodied ship captains to attend a muster within the Koronous expanse. Come be apart of history and bring death and war to the enemies of man! All glory to the Emperor!